With the rapid development of touch screens, the touch screens have already dominated the flat-plane display (FPD). There is a great desire for manufacturers to design high-performance and low-cost touch screens in the limited space without changing display effects with the required optical properties and electrical properties of the display continually improved, as well as the continually demand for thinner display by customers.
The structure design shown in FIG. 1 is the typical one adopted in the panel of currently conventional capacitive touch screens, which comprises a longitudinal sensing electrode group and a lateral drive electrode group. The sensing electrode group and the drive electrode group are insulated from each other and they each form a capacitor with a common electrode; each of the sensing electrode group and the drive electrode group is connected with sensing leads 4 at one side; wherein the drive electrode group includes a plurality of drive electrodes 1 in series, the plurality of drive electrodes 1 are connected through metal connection bridges 3; the sensing electrode group includes a plurality of sensing electrodes 2 in series. As an electrical field is existed in a human body, touching a surface of the capacitive touch panel with a finger results in a coupling capacitance formed between the finger and the sensing and drive electrodes of the touch panel. Due to the change of capacitance at the touching point, currents are induced in the sensing and drive electrodes, to flow toward the touching point. The induced current has intensity inversely proportional to a distance between the finger and a boundary of the touch panel. Positions of the touching point can be accurately computed by measuring the induced currents with sensors connected to the sensing and drive electrodes via sensing leads. In the prior art, each of electrodes in the electrode group has same size.
In a practical application, since the touching points have different distance from the sensing leads, the sensor will cost a longer time to receive the induced current when the touching point is far away from the sensing leads 4, so that a signal delay is presented. In the panel shown in FIG. 1, the electrode which is far away from the sensing lead 4 has a lower sensitivity than the electrode near the sensing leads 4, thus, the farther away from the sensing leads the position is, the lower the sensitivity is in the capacitive touch screen. This difference between the sensitivities is adverse to the effective touch control of the capacitive touch screen, and it reduces the satisfaction to the products by the customer.